2.3.4 Internal Symmetry

The internal symmetry involves counting the number of times a symmetry structure exists within the target molecule. Currently the internal symmetry is calculated by the number of symmetry groups matching a carbon atom where three groups are the same and the fourth different. Each contributes a multiplicative factor of 3. This structure is represented by the general carbon atom bonding shown in Figure 3. The associated table (similar to Table 10.4) has two groups, one group denoting three equivalent connecting substructures and one group with the remaining substructure. In the notation of the previous section this is C(B₁)(B₂)³ where B1 and B2 are arbitrary connecting groups. For example, terminal methyl groups and the second carbon in 2,2-dimethylpentane match this symmetry description.